\begin{frame}
  \frametitle{Linear Functions: Example}
  
  \begin{exampleblock}{}
    When dry air moves upward it expands and cools.
    \begin{itemize}
    \pause
      \item ground temperature is $20\textdegree$
    \pause
      \item temperature in height of $1$km is $10\textdegree$
    \end{itemize}
    \pause
    Express the temperature as a linear function of the height $h$.\\
    What is the temperature in $2.5$km height? 
  \end{exampleblock}
  \pause\smallskip
  
  Since we are looking for a linear function:
  \begin{talign}
    T(h) = m h + b
  \end{talign}
  \pause
  We know that:
  \begin{talign}
    T(0) &= m\cdot 0 + b = 20 \mpause[1]{\quad\implies\quad b = 20}\\
    \mpause[2]{T(1) }&\mpause[2]{= m\cdot 1 + b = m\cdot 1 + 20 = 10 }\mpause[3]{\quad\implies\quad m = 10-20 = 10}
  \end{talign}
  \pause\pause\pause\pause
  Thus $T(h) = -10m + 20$, \pause
  and $T(2.5) = -5\textdegree$.
\end{frame}